We consider the perturbation of the classical Bessel moment functional by the addition of the linear functional M0 (x) + M1 0 (x), where M0 and M1 2 IR. We give necessary and su cient conditions in order for this functional to be a quasi-de nite functional. In such a situation we analyze the corresponding sequence of monic orthogonal polynomials B ;M0;M1 n (x). In particular,
a hypergeometric representation (4F2) for them is obtained.
Furthermore, we deduce a relation between the corresponding Jacobi matrices, as well as the asymptotic behavior of the ratio B ;M0 ;M1 n (x)=B
n (x), outside of the closed contour containing the origin and the di erence between the new polynomials and the classical ones, inside.